Motor truck

ABSTRACT

A motor truck comprising energy transforming means located between a chassis frame and a rear body and adapted to allow an upward movement of the body relative to the frame to absorb kinetic energy of the body upon collision.

This is a continuation of prior Application Ser. No. 503,398, filedSept. 5, 1974, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to a motor truck in which impact force affectingthe crew in the truck upon collision is absorbed.

Due to heavy gross vehicle weight of motor trucks, conventional energyabsorbing systems for protecting the crew in the trucks upon collisionmust have larger size than that used for motor cars to absorbsufficiently the impacting energy. In the conventional energy absorbingsystems, acceleration of gravity applied to the crew upon the collisionbecomes great because of great additional force resulting from a rearbody and a load thereon, though a chassis frame is capable of absorbingthe energy by its inherent plastic deformation.

SUMMARY OF THE INVENTION

To avoid the above drawbacks, this invention provides a motor truckcomprising energy transforming means located between a chassis frame anda rear body and adapted to allow an upward movement of said bodyrelative to said frame by a longitudinal impacting force, therebyabsorbing kinetic energy of the body.

When a vehicle collides against the motor truck according to theinvention and the impacting force acting onto the rear body of the truckexceeds a predetermined value, the body is moved upwardly by means ofthe energy transforming means and the chassis frame is urged downwardlyby a reaction of the upward movement of the body, since the combinedweights of the body and the load thereon occupy more than a half of thegross vehicle weight of the truck. Therefore, longitudinal kineticenergy acting onto the rear body upon the collision of the vehicle istransformed into potential energy through the upward movement of thebody in opposition to the gravity. The kinetic energy is also absorbedthrough depression of the chassis frame and sequent deformation ofsuspensions by the reaction of said upward movement. Furthermore, thekinetic energy is absorbed through plastic deformation of U-boltstightening the frame and the body upon the upward movement thereof.Therefore, in the conventional motor truck whole kinetic energygenerated upon collision acts on the chassis frame in the longitudinaldirection thereof, but in the truck according to the invention thekenetic energy is absorbed as described above so that the impactingforce affecting the crew in a cab through the chassis frame is reduced.Also, when the body is moved upwardly upon the collision of vehicle andthe chassis frame is depressed by the reaction of upward movement of thebody, the wheel are urged on the ground through the suspensions so thatthe motor truck according to the invention is sufficiently brakedwithout locking and effectively prevented from its forward movement uponbraking operation of the crew, also the kinetic energy received from thevehicle is absorbed upon said braking operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a side view of one embodiment of a motor truck according tothe invention,

FIG. 2 shows a side view of a part of FIG. 1,

FIG. 3 shows a cross-sectional view taking along the line III--III inFIG. 2,

FIG. 4 shows a side view of assembling part of the U-bolt in FIG. 1,

FIG. 5 shows a cross-sectional view taking along the line V--V in FIG.4,

FIG. 6 shows a first modified view of FIG. 4,

FIG. 7 shows a cross-sectional view taking along the line VII--VII inFIG. 6,

FIG. 8 shows a second modified view of FIG. 4, FIG. 9 shows across-sectional view taking along the line IX--IX in FIG. 8,

FIG. 10 shows a third modified view of FIG. 4,

FIG. 11 shows a cross-sectional view taking along the line XI--XI inFIG. 10

FIG. 12 shows a partial side view of the truck in FIG. 1, with a bumperat the rear of its body,

FIG. 13 shows a side view of another embodiment of a motor truckaccording to the invention,

FIG. 14 shows a side view of a part of FIG. 13,

FIG. 15 shows a cross-sectional view taking along the line XV--XV inFIG. 14,

FIG. 16 shows a side view of a part of further embodiment of a motortruck according to the invention, and

FIG. 17 shows a cross-sectional view taking along the line XVII--XVII inFIG. 16.

DETAILED DESCRIPTION

In the first embodiment shown in FIGS. 1 to 3, a cab-over type motortruck 1 has a cab 2, a chassis frame 3, a rear body 4, wheels 5 andenergy transforming means 6. The cab 2 is secured to the frame 3. Theframe 3 and the body 4 are fixed by means of U-bolts 41 through abolster 7 securely fixed to the body. The U-bolts 41 are stretchablethrough its plastic deformation when tensile force applied to theU-bolts exceeds a predetermined value.

As seen from FIGS. 4 and 5, the U-bolt 41 holds the frame 3, areinforcing member 3', a cushion 9 and the bolster 7 and the upper endof the U-bolt passing through a washer plate 42 is tightened by a nut 44through belleville springs 43. The belleville springs 43 are providedfor relieving an initial impacting force.

In the first modification of the U-bolt 41, as shown in FIGS. 6 and 7,two bolts 45 hold the chassis frame 3 and upper and lower ends of thebolt 45 pass through washer plates 46 and 47 respectively. A die 48 isfitted on a stepped diameter portion of the upper end of the bolt 45while the lower end thereof is tightened through belleville springs 49by means of a nut 50, so that the larger diameter portion of the upperend is extracted through the die 48 upon the upward movement of the rearbody 4.

In the second modification of the U-bolt, as shown in FIGS. 8 and 9, adie 52 and a washer plate 53 are fitted on upper end of the bolt 51. Thewasher plate 53 has no flat portion, such as the washer plates 42 and46, which contacts with the bolster 7, but has a periphery arcuated inits cross section and contacted with the bolster 7. The washer plate 53has a bore 54 through which the bolt 51 passes. The diameter of the bore54 is greater than that of the bolt 51 to provide a sufficient clearancebetween the bolt and bore. Therefore, even when the bolt 51 is inclinedrelative to the bolster 7 upon the relative movement between the bolt 51and the rear body 4 in the longitudinal and vertical directions, anexternal periphery of the washer plate 53 is easily inclined integrallywith the upper end of the bolt 51 due to arcuation of the plate withouteffecting bending force to the upper end of the bolt, thereby causing asmooth extraction of the bolt through the die 52.

In the third modification of the U-bolt, as shown in FIGS. 10 and 11,there is provided a washer plate 55 which is integrated with the washerplate 53 and the die 52 in the second modification to achieve the sameeffect as said modification.

An upward movement limiting means 75 for the rear body 4, as shown inFIG. 4, is fixed to the chassis frame 3 by means of a shear bolt 76 tolimit the rear body 4 to move upwardly more than a desired height forexample the height of the bolster 7 when the shear bolt 76 is shearedupon collision. The upward movement limiting means 75 consists of aframe formed by rigid channel members which holds the chassis frame 3and the body 4 by its upper and side edges and has a space same as theheight of the bolster 7 between its lower edge and the lower edge of thechassis frame 3.

Furthermore, shear plates 78 or shear bolts, not shown, which aresheared by an impacting force greater than a predetermined value arefixed between the rear body 4 and the chassis frame 3, thereby limitingnormally the longitudinal movement of the body 4 relative to the frame3. The wheels 5 are mounted on the frame 3 through leaf springs and, ifdesired, shock absorbers, not shown.

In FIGS. 2 and 3, the energy transforming means 6 consists of a plate 62fixed to the frame 3 by means of bolts 60 and having a linear slidingsurface 61 inclined forwardly and upwardly and a plate 65 fixed to thebolster 7 by means of bolts 63 and having a sliding surface 64contacting with the surface 61.

A lod 4' is carried on the rear body 4. A stopper 8 is fixed on theframe 3 in front of the body 4 to prevent sliding movement of the body 4when the latter slides forwardly on the frame 3 by an abnormal impactingforce. Instead of the stopper 8 an absorbing member for catching themoved rear body may be fixed on a rear edge of a cab mounting 10 or anengine may be mounted such that an upper portion of its rear end ispositioned near to the rear of the cab 2 and above the chassis frame 3,thereby preventing the forward movement of the body 4. A cushion 9 maybe located between the frame 3 and the body 4 for absorbing pressures onrespective surfaces thereof. Also, a bumper 7' may be fixed to the rearend of the bolster 7 of the rear body 4 through stays 7" to catch animpacting force by the collision at the rear of the body 4, as shown inFIG. 12.

When the vehicle collides against the rear body 4 of the motor truck 1and the body 4 receives an impacting force greater than thepredetermined value, the shear plates 78 are sheared and the body 4 ismoved forwardly. Therefore, the body 4 is moved upwardly relative to thechassis frame 3 along the forwardly and upwardly inclined slidingsurfaces 61 and 64 of the energy transforming means 6. Upon the upwardmovement of the body 4 each U-bolt 41 is stretched vertically to causeits plastic deformation, thereby absorbing the kinetic energy for theupward movement of the body, and said movement is securely preventedfrom exceeding a predetermined height by the upward movement limitingmeans 75. As the combined weights of the body 4 and the load thereonoccupy more than a half of the gross vehicle weight, the force urgingthe body 4 upwardly is great and the frame 3 is depressed by itsreaction. The kinetic energy depressing the frame 3 is absorbed throughthe leaf springs and the shock absorbers. Also, the wheels 5 are urgedon the ground by the reaction of said depressing force. Furthermore,upon upward movement of the body 4 the sliding surfaces 61 and 64 of theplates 62 and 65 slide relatively to each other so that the kineticenergy of the body 4 is absorbed by the frictional resistancetherebetween.

Therefore, the kinetic energy acting onto the rear body 4 by thecollision of the vehicle is absorbed by the U-bolts 41, the leaf springsand the shock absorbers. The impacting force affecting the crew in thecab 2 through the chassis frame 3 is absorbed through the plasticdeformation of the U-bolts 41 and the transformation into the potentialenergy mainly by the upward displacement of the body 4 relative to theframe 3. Thus, in the motor truck according to the invention, thekinetic energy of the body 4 will not wholly effect forwardly as theconventional motor trucks and the acceleration of gravity applied to thecrew is relieved. As the body 4 and the load thereon which occupy morethan a half of the gross vehicle weight are moved upwardly upon thecollision, the reaction force against said movement is great and thewheels are urged onto the ground by said reaction force. As the frictionforce between the wheels and the ground becomes great by said forceurging the wheels onto the ground when the truck 1 is braked such asstopping, the forward movement of the truck 1 is effectively prevented,thereby reducing the possibility that the truck 1 collides against avehicle in front of it. The impacting force applied to the crew in thecab 2 is also relieved since the forward movement of the truck 1 isprevented by said friction force.

The operation of the above embodiment will be described when the truckis collided from behind, but the same effect is obtained when the truckcomes into a head-on collision.

In the second embodiment as shown in FIGS. 13, 14 and 15, instead of theplate 62 and 65 of the energy transforming means 6 in the firstembodiment with the linear sliding surfaces, an energy transformingmeans 90 comprises a plate 92 having a sliding surface 91 of forwardlyupward paraboloid shape and fixed at its upper portion to the bolster 7by means of bolts 93 and a plate 95 fixed to the chassis frame 3 bymeans of bolts 96 and having a sliding surface 94 which is formed from aconvex surface having a relatively small curvature and contacts with thesliding surface 91. A friction plate 11 is located between the frame 3and the body 4 instead of the cushion 9 in the first embodiment. When astrong impacting force is applied to the rear body 4 by the collision,initially a substantially horizontal portion 191 of the sliding surface91 of the plate 92 slides on the plate 95 so that the body 4 slides onlyforwardly relative to the frame 3 without causing its upward movementbut with a progressively increasing lifting action of the body followingon continued forward movement of the body on the frame as rearwardlypositioned portions of the surface 91 engage the surface 94. Thefriction plate 11 exhibits sufficiently its function to absorb some ofthe kinetic energy of the body 4. Upon forward displacement of the body4 relative to the frame 3 at the rising portion of the sliding surface91, the body 4 moves upwardly to absorb sufficiently said kinetic energyas described in the first embodiment. In this case, the frame 3 and thebody 4 are tightened as in the first embodiment by the U-bolts 41 whichare plastically deformed upon receiving the vertical tensile forcegreater than a predetermined value.

In the third embodiment as shown in FIGS. 16 and 17, instead of usingrespective plates of energy transforming means 6 and 90, an energytransforming means 100 comprises a plate 101 which is fixed at its lowerportion to the chassis frame 3 by means of bolts 102. The upper portionof the plate 101 is provided at right hand side in FIG. 16 with a bore104 through which a bolt 103 passing through the bolster 7 is insertedand with a slot 105 which is curved forwardly and upwardly from the bore104 and has a width much narrower than the diameter thereof. The bolt103 passing through the bolster 7 and the plate 101 is tightened by anut 106. When the strong impacting force in the direction of movement ofthe truck 1 is applied to the rear body 4, the bolt 103 spreads out theslot 105 to move the body 4 upwardly therealong, thereby absorbing thekinetic energy for the body 4 by the upward movement thereof and thespreading of the slot 105.

In this embodiment the plate 101 is fixed to the frame 3 and the belt103 is mounted in the bolster 7 of the body 4, but it may be arrangedthat the plate 101 is fixed to the bolster 7 of the body 4 while thebolt 103 is fixed to the frame 3 to come into engagement of the boltwith the forward end of the slot.

In the above described embodiments, there is described the case when therear body 4 is moved forwardly relative to the chassis frame 3 upon thecollision, but the kinetic energy of the rear body 4 is absorbed in caseof the rearward movement of the body 4 by, for example, the impactingforce caused by the collision of another vehicle against the frame 3 byway of the reverse attachment of the energy transforming means.

What is claimed is:
 1. A motor truck comprising a frame device, a bodydevice movable relative to the frame device, bolt members extendingvertically at opposite sides of said frame and body devices to hold saiddevice together, a die member being fitted on a stepped diameter portionat one respective end of each of the bolt members and having a peripherythat is arcuate in section and in operative contact with one of saiddevices, and an energy transforming means including a first plate memberfixed to one of said devices and having a first parabolic slidingsurface and a second plate member fixed to the other of said devices andhaving a second parabolic sliding surface, which slidably contacts withat least a portion of said first sliding surface of said first member,said first sliding parabolic surface including a forwardly projecting,substantially horizontal, gradually descending leading portion inlimited engagement with said second parabolic sliding surface; said bodydevice being moved upwardly by said energy transforming means when alongitudinal impacting force of or greater than a predetermined value isapplied, whereby said stepped diameter portion of the bolt member ispulled through the die to cause its deformation to absorb kinetic energyof the body device.
 2. A motor truck according to claim 1, furthercomprising at least one shear plate fixed between said body and framedevices and adapted to be sheared by said longitudinal impacting force,but normally limiting the relative movement of said devices.
 3. A motortruck according to claim 1, wherein a washer plate is positioned betweensaid die member and said one device, said washer plate having an innerface supporting the arcuate surface of said die and an outer face ofarcuate contour engaging said one device.
 4. A motor truck according toclaim 3, wherein said washer plate extends transversely of the motortruck and its arcuate outer face extends in the direction oflongitudinally of the motor truck.
 5. A motor truck according to claim3, wherein said die member is at an upper end of said bolt members and aspring means engages a lower end of said bolt members and said springmeans comprises a plurality of Bellville springs secured in position oneach bolt member by an attachment nut.
 6. A motor truck comprising aframe device, a body device movable relative to the frame device, boltmembers extending vertically at opposite sides of said frame and bodydevices to hold said devices together, a die member being fitted on astepped diameter portion at one respective end of each of the boltmembers and being in operative contact with one of said devices, and anenergy transforming means including a first plate member fixed to saidbody device and having a lower parabolic sliding support surface and asecond plate member fixed to said frame device and having an uppersliding support surface which slidably contacts with at least a portionof said sliding surface of said first member; said parabolic supportsurface including a forwardly projecting, substantially horizontal,gradually descending leading portion in limited engagement with saidupper sliding support surface, said body device being moved forwardlyand upwardly by said energy transforming means when a longitudinalimpacting force of or greater than a predetermined value is applied,whereby said stepped diameter portion of the bolt member is pulledthrough the die to cause its deformation to absorb kinetic energy of thebody device.
 7. A motor truck according to claim 6, further comprisingat least one shear plate fixed between said body and frame devices andadapted to be sheared by said longitudinal impacting force but normallypreventing relative movement of said devices, relative forward movementof said body device on said frame device being frictionally resisted bymeans supporting said body device on said frame device, said body devicemoving forwardly on said frame device when it receives an impact of orgreater than a predetermined value and gradually bringing differentareas of said parabolic sliding surface into engagement with said uppersliding support surface for a progressively increasing lifting action onsaid body device.
 8. A motor truck according to claim 7, wherein awasher plate is positioned between said die member and said one device,said washer plate being of substantially U-shape in vertical section andhaving an inner face supporting the arcuate surface of said die and anouter face of arcuate contour engaging said one device, said washerplate extending transversely of said motor truck.